Abstract

It was found that the decrease of the multiple quantum well(MQW) growth temperature from 865 to 810 °C leads to a MQW emission wavelength shift from the violet to the green spectral region. The lowering of the growth temperature also promotes a decrease of the MQWphotoluminescence(PL) intensity at high excitation and a disappearance of the excitonic features from the low-temperature reflection and PLspectra of GaN barriers and claddings. The laser threshold dependence on is not monotonic, with the lowest value of at . High-temperature annealing (900 °C, 30 min) leads to a twofold increase of the PL efficiency only from the InGaNQWs grown at the lowest temperature. The results allow one to explain the laser threshold behavior in terms of the heterostructure quality, the defect concentration, In clusterization, and the piezoelectric field dependence on the MQW growth temperature.